1. Field
Apparatuses and methods consistent with exemplary embodiments relate to a signal processing method, an encoding apparatus using the signal processing method, a decoding apparatus using the signal processing method, and an information storage medium, and more particularly, to a signal processing method for inserting additional information into or extracting additional information from a bitstream, an encoding apparatus using the signal processing method, a decoding apparatus using the signal processing method, and an information storage medium.
2. Description of the Related Art
To compress and transmit an audio signal, and receive the compressed audio signal and decompress the compressed audio signal into the original audio signal, a transmitting side uses an encoder and a receiving side uses a decoder. The transmitting side and the receiving side compress and decompress an audio signal according to a predetermined standard.
As one of standards for transmitting audio signals, there is Audio Coding (AC)-3. The AC-3 refers to a third form of audio coding schemes developed by US Dolby Laboratories, Inc., and is a standard for an audio part of digital video discs (DVDs). The AC-3 uses 5.1 channels to produce a sound. More specifically, the AC-3 uses 5.1 channels which separate and output audio signals through 6 speakers including 5 speakers installed in Left, Right, Center, Left Surround, and Right Surround positions and a subwoofer speaker for a low-frequency effect.
Recently, to implement a more stereoscopic audio system, a method and apparatus for generating an audio signal by expanding the number of audio channels more than 5.1 channels has been developed. For example, an audio system having 10.2 channels capable of outputting separated audio signals through 12 speakers has been developed.
The AC-3 standard limits the number of compressible audio channels to a maximum of 5+1=6. As a result, the AC-3 may generate and transmit only a bitstream through 5.1 channels, and when the number of audio channels exceeds 6, a bitstream cannot be generated and transmitted.
The Enhanced AC-3 standard, which is an improvement of the AC-3 standard, limits the number of compressible audio channels to a maximum of 13.1. Therefore, for more than 13.1 channels, a bitstream cannot be generated and transmitted according to the Enhanced AC-3 standard.
Accordingly, a method and apparatus for extending a function provided by a stream while complying with the AC-3 or Enhanced AC-3 standard has been developed, and there is a need for a signal processing method and apparatus capable of providing various functions.